The present invention relates to an electro-surgical apparatus.
There are electrosurgical apparatuses which coagulate or dissect organic tissues using high-frequency power. Such an electrosurgical apparatus generates high-frequency power inside its main body and supplies the high-frequency power to a monopolar instrument or bipolar instrument, connected to the main body, for treatment of organic tissues.
Jpn. Pat. Appln. KOKAI Publication No. 8-196543 discloses an impedance monitoring apparatus which monitors the impedance of an organic tissue while this tissue is being treated with high-frequency power. More specifically, this apparatus measures the minimum impedance and uses a function of this minimum impedance to determine the impedance of the point of time when tissue coagulation is completed.
As the electrosurgical apparatus described in the aforementioned Jpn. Pat. Appln. KOKAI Publication No. 8-196543 detects the end of tissue coagulation based only on the function of the minimum impedance, the detection result considerably varies depending on the types of tissues or the clamping state of forceps, which may result in overburning. Apparently, this apparatus cannot guarantee a stable coagulation performance.
There is another method which detects the end of tissue coagulation using the rate of change in impedance, but which has a drawback similar to that of the above method of detecting the end of tissue coagulation using the impedance.
The prior art including the one disclosed in the mentioned Jpn. Pat. Appln. KOKAI Publication No. 8-196543 employs fixed conditions for detecting the end of tissue coagulation and thus cannot arbitrarily change the coagulation level.
Accordingly, it is a primary object of the present invention to provide an electrosurgical apparatus capable of surely stopping the output at the end of coagulation to avoid overburning.
It is a secondary object of this invention to provide an electrosurgical apparatus which can change the coagulation level according to a user""s selection by changing a condition for detecting the end of coagulation.
To achieve the first object, according to the first aspect of this invention, there is provided an electrosurgical apparatus for supplying high-frequency power from a high-frequency power supply unit to an instrument placed in association with an organic tissue to dissect or coagulate the organic tissue, which said electrosurgical apparatus comprises:
an impedance calculating section for calculating an impedance value of the organic tissue;
a rate-of-impedance-change calculating section for calculating a rate of impedance change of the organic tissue based on the impedance value calculated by the impedance calculating section; and
a control section for controlling a high-frequency output of the high-frequency power supply unit based on a predetermined condition provided by an evaluation of both the impedance value calculated by the impedance calculating section and the rate of impedance change calculated by the rate-of-impedance-change calculating section.
To achieve the first object, according to the second aspect of this invention, there is provided a control apparatus, connected to an electrosurgical apparatus having an instrument for performing a predetermined treatment on an organic tissue and a high-frequency power supply unit for supplying high-frequency power for treating the organic tissue to the instrument, for controlling the high-frequency power output from the high-frequency power supply unit, which control apparatus comprises:
an impedance calculating section for calculating an impedance value of the organic tissue;
a rate-of-impedance-change calculating section for calculating a rate of impedance change of the organic tissue based on the impedance value calculated by the impedance calculating section; and
a control section for controlling a high-frequency output of the high-frequency power supply unit based on a predetermined condition provided by combining the impedance value calculated by the impedance calculating section with the rate of impedance change calculated by the rate-of-impedance-change calculating section.
To achieve the second object, according to the third aspect of this invention, there is provided an electrosurgical apparatus for supplying high-frequency power from a high-frequency power supply unit to an instrument placed in association with an organic tissue to coagulate or dissect the organic tissue, which apparatus comprises:
a setting section for setting a coagulation level comprising at least one variable representing an end of coagulation in a variable manner prior to a coagulation operation;
a detection section for detecting a coagulation state of the organic tissue in a coagulation operation; and
a control section for controlling a high-frequency output of the high-frequency power supply unit based on the coagulation level set by the setting section and the coagulation state detected by the detection section.
To achieve the second object, according to the fourth aspect of this invention, there is provided a control apparatus, connected to an electrosurgical apparatus having an instrument for performing a predetermined treatment on an organic tissue and a high-frequency power supply unit for supplying high-frequency power for treating the organic tissue to the instrument, for controlling the high-frequency power output from the high-frequency power supply unit, which control apparatus comprises:
a setting section for setting a coagulation level of a tissue in a variable manner;
a detection section for detecting a coagulation state of the organic tissue in a coagulation operation; and
a control section for controlling a high-frequency output of the high-frequency power supply unit based on the coagulation level set by the setting section and the coagulation state detected by the detection section.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.